1. Field of the Invention
This invention relates to a process for making coextruded cookies. In particular, this invention relates to a process for making coextruded cookies having crisp external cookie-like casing compositions of a high sugar content and soft internal cream filling compositions of a high sugar content. This invention includes the product of this process.
2. Description Of The Prior Art
Extruders have been used in food technology for many years. A wide variety of food products can be formed by the use of extruder technology. Food products can be cooked during extrusion or extruded and then transferred to an oven and baked. Typically, extruded food products form a single mass of food material. When a product is "coextruded" an external casing of food material is simultaneously formed around an internal filling of a different food material. The coextruded product is a single mass of two types of food materials. The two food materials can have different densities and functions. Frequently, the internal filling is of a texture similar to that of the external casing. Very often, coextruded food products are not cooked during extrusion, but are formed and cooked during a separate step.
Extruded cookies having a soft internal filling are typically manufactured by a two step process. In the first step the external casing is extruded and is either cooked during extrusion or baked after extrusion. During the second step the external casing is filled with a filling or other composition. This process is a time consuming operation and requires much manipulation of the external casing pieces in order to fit the casings into filling apparatuses. This additional manipulation can cause excessive product breakage.
The coextrusion of a food product having two greatly different textures, one for the external casing and one for the internal filling, causes numerous problems. One problem often encountered in this situation occurs when the internal filling and external casing require different processing and/or cooking temperatures. Failure to satisfy this requirement can result in caramelization of one layer or the other before the entire food product is properly cooked. Another problem is encountered when the internal filling and external casing have different expansion rates. An over expansion of the internal filling can either create back-up of ingredients within the extruder or can cause the internal filling to leak out of the external casing when the food product is cut into distinct pieces.
U.S. Pat. No. 4,275,647 to Chambers et al. discloses an apparatus for producing a center filled food product. The casing composition disclosed for use with this apparatus is a mixture of mono and/or disaccharides, flour, shortening, egg whites, and water. The external casing is identified as having a "relatively high content of mono and/or disaccharides". The disaccharide content is between 15% and 45% and the flour content is between 10% and 20% by weight of the dough. The filling composition is between 25% and 50% sugar, between 10% and 40% fat, and between 10% and 40% non-fat dry milk solids by weight of the mix. The product of this invention is formed by a two step process. In the first step the apparatus performs cold extrusion of the casing composition which is baked as a flat sheet and rolled around its longitudinal axis to form a continuous tube. In the second step the filling composition is injected into the core of the continuous tube. The continuous tube is filled after the extruded flat sheet is rolled.
U.S. Pat. No. 4,469,475 to Krysiak discloses a machine for making encrusted food products. These food products can contain an internal filling which is coextruded into an external casing of dough. This apparatus is not a cooker coextruder in which the external casing and internal filling are cooked during the coextrusion process. Cooking is required as an additional step.
U.S. Pat. No. 3,541,946 to Johnston discloses an apparatus for continuously producing a center filled puffed cereal product. The apparatus of the disclosed invention is an extruder having a die head. The dough that forms the external casing of the center-filled puffed cereal product is compressed and heated by a rotating screw within the extruder. The compressed and heated dough expands as it exits the die head. A viscous fluid also under pressure is introduced to the extrusion die head through a feed pipe passing through the die head. The viscous fluid is simultaneously introduced to the interior of the expanding dough as the dough expands. The center-fill fluid does not flow through the extruder. This apparatus does not heat the center-fill fluid. This patent does not disclose an apparatus that cooks both the external casing and internal filling during the coextrusion process.
U.S. Pat. Nos. 4,115,502 to Rasmussen, 4,015,518 to Roth et al, and 3,615,147 to Hayashi all disclose apparatuses for extruding food products. The Roth and Hayashi references are particularly concerned with food products having an internal filling. These references disclose a process for producing uncooked food products. These references do not disclose a process for continuously coextruding cream filled cookies.
U.S. Pat. No. 4,416,910 to Hayashi et al. discloses an apparatus for continuously coextruding a center filled dough product. In this process the dough is filled with butter for use in an apparatus that flattens, stretches, and folds the dough to make multi-layered products such as pies, pastries and the like. This reference does not disclose a process for continuous coextrusion cooking.
The industry is lacking a coextruded cookie and a method for producing a coextruded cookie having a high sugar external casing and a soft internal filling.